Telegraph and telephone system.



-J. SCHIESSLER. TELEGRAPH AND TELEPHONE SYSTEM.

APPLICAUON min MAY 22. 1914.

1,2Q9J96. Patented. 51111 12, 1917.

J'OSEFv SCHIESSLER, BADEN, NEAR VIENNA, AUSTRIA.-

TELEGRAPH AND TELEPHONE SYSTEM.

Specification of Letters Patent.

' Patented June 12, 1917.

Original application filed February 7, 1912, Serial No. 675,990. Dividedand this application filed May 22, 1914. Serial No. 840.236.

To all whom it may concern:

Be it known that I, Dr. Josnr SoHInss- LER, subject of the Emperor ofAustria, r'esiding at Baden, near Vienna, Austria, have invented certainnew and useful Improvements in Telegraph and Telephone Systems; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings, and to letters or figures of reference markedthereon, which form a part of this specification, being a division of myapplication Serial No. 675,990, filed February 7, 1912.

This invention relates to electric telegraphy or telephony by submarinecables and long distance overhead lines, and has for its object toovercome the difficulties which arise in connection with sucharrangements owing to the great capacity of the lines.

The systems heretofore known for compensating the detrimental efiects ofsuch capacity consist either in an iron-wire spiral wound all over thelength of such cable or are based on the well known method of Pupin,which provides a series of self .induction coils connected with the lineat certain distances throughout its whole length. Now this inventionprovides a new system for attaining the object above mentioned, whichwill result in using such cables for telegraphy or telephony with greatefliciency and much less cost than with the sys tems heretofore used,while at the same time none of the disturbances will occur, which aredue to the coils, spread over the line, that in most cases (for instancein submarine cables) cannot be inspected or overhauled.

The system used will now be described with reference to the accompanyingdrawing in which Figure 11s a diagrammatic view oftwo stations connectedby a submarine cable or other long distance line. trates a modification.

Referring toFig. 1 two stations A and B are shown at the respective endsof the submarine cable or other long distance line 11; the station A isrepresented in position for transmitting messages, while station B is inreceiving position. As is shown in this figure the arrangement in bothsta;

Fig. 2 illustions is identical. The cable or other line is provided atboth stations with a condenser 2 and 2 respectively of appropriatecapacity, which are connected with one terminal of the coils 3 and 3respectively of coupling transformers. In parallel to the coils 3 and 3variable condensers a and 4 are placed which together with the coils 3and 3 form oscillation circuits II and II capable of being tuned toresonance with each other and with the frequency of another circuit IIIand. III respectively, formed by the primary coil 15 (15) of thecoupling. transformer in-parallel to which a similar condenser 16 (16)may be connected. The second terminal of the transformer coil 3 (3) isconnected with a double lever switch 6 (6). This switch connects by itsterminals 9, 11 or 10, 12 (9, 11 or 10, 12) the positive and thenegative poles respectively of a high tension direct current generator 8(8) with the coil 3 (3) and the cable, while the second lever leadingfrom the second terminal of the generator is grounded through theadjustable self induction coil 7 (7).

This grounding is performed with metallic plates of suitable magnitudeor by a metallic net work submerged into the water or buried intheground. IVhen a source of direct current is used a choking coil 5 (5)provided with an iron core is preferabbybsed in series with thetransformer coil 3 3 At the receiving station the double lever switchoccupies its second position on the terminals 9, 11 thus connecting thepoles opposite to thoseof the transmitter station with the cable and theground.

The circuit III (III) is likewise connected'with a double lever switch17 (17) capable of connecting this circuit with either the terminals 19,21, (19, 21) of the trans mitter or with the terminals 18, 20, (18, 20)of the receiver. The transmitter circuit IV (IV) comprises a tunedinterrupter 14a source of current 27 (27) connected with one terminal 19(19) of the double lever switch over said interrupter and branched offat its other side into two parallel branches which contain a Morse key25 (25) for telegraphy or a telephonic transmitter 26 (26) respectively.A switch 22 (22) is provided for either connecting the Morse key or thetelephonic transmitter with the other terminal 21 (21) of the doublelever switch. A variable condenser 28 (28) may with advantage beconnected in parallel to the said terminals 19 and 21 (19 and 21').

The receiving apparatus 30 (30') is shown switched in at station B atterminals 18, 20. In parallel with the receiving apparatus an adjustableself induction coil and a condenser 31 (31') may preferably be arranged;it has further been found that it is of advantage to provide in thiscircuit V a special high tension current intensity 29, Fig. 2, so thateven a voltaic pile or a Zamboni dry pile can be used for this purpose.This source of current 29 can be in parallel with the receivingapparatus and a blocking condenser B K may or may not be used inconnection with the same.

From the foregoing it will be seen that the submarine cable or otherline of great capacity forms together with the condensers 2 and 2 andthe self induction coils 7 and 7, 3 and 3, an oscillatory circuit whichmay be traced from ground 13 over coil 7, double lever switch contact 12to the negative pole of the high tension direct current source, and fromthe positive pole of said source over the coils 5 and 3 to the condenser2, the cable 11 the condenser 2 the coils 3 and 5, the contact 9 ofdouble lever switch 6 to the negative pole of the direct current source8 and from its positive pole to double lever switch contact 11 over coil7 to ground 13 and back to ground 13. Instead of the ground connectionsa return line may be used.

This oscillatory circuit is charged by the high tension generators in acontinuous way and the impulses of the transmitting apparatus aresuperposed on this tension by means of the circuit II (or II resp.) Thusthe resistance of the line need not be overcome by the feeble impulsesbut is overcome by the charging current generated at 8 and 8 andtherefore these impulses will have a much greater intensity whenincoming.

Furthermore special receiving apparatus is used, which converts thosefeeble undulations into well marked signals of the kind desired.

As it has been stated previously in this oscillatory circuit there arecontained the oscillatory circuits II and II respectively, which can betuned to resonance with each other and with the circuits III and IIIrespectively, by means of the variable condensers 4t and 1. Theoscillatory circuit II is excited in the transmitting station preferablyby impulse excitation, so as to perform free oscillations, which aresuperposed on the circuit. The impulse excitation (method of M. Wien) isproduced by a syntonized interrupter 14 for instance a tuning forkinterrupter, a buzzer, a phonic relay or the like, in the transmittingcircuit IV which is switched in or out by the Morse key, thus forminggroups of oscillations in the secondary circuit, which are bysuperposition on the line transmitted to the station B. Now, if thisstation has tuned its circuit II to the same frequency, the oscillationstransmitted by the line will occur only in this circuit, and with theseoscillations also the interruptions produced by the Morse key.

It is now obvious that in the case of a plurality of oscillationcircuits as indicated on the drawings in dotted lines, being switched inat the receiving station and tuned to a frequency dilferent to eachother, messages of different stations, or a plurality of messages fromone station can be transmitted, as according to the well known law ofBernoulli these oscillations after having passed in common the cablewill in the syntonized receiving circuits be decomposed into theiroriginal elements. 7

Thus a very simple kind "of multiplex telegraphy is rendered possiblethat is based only on the syi'itonizin'g of the oscillation circuits IIand II, which can be very easily performed.

In the same way a multiplex telephony can be obtained, only slightmodifications of the circuits beingnecessary. The waves due to spokensounds must in this case be superposed directly on the secondary circuitII, as it would not be possible to obtain good results by theirsuperposition on the interrupter circuit. In the receiving station theoscillations thus obtained are then again decomposed into their elementsby the syntonization of the circuits;

Operation.

A description of the general system and the apparatus used having beengiven, the operation of the same will be explained in the following:

Referring to Fig. 1 the station which has to transmit telephonic ortelegraphic signals or messages switches in contacts 10 and 12 andcontacts 19 and 21 by means of the double lever switches 6 and 17respectively, thus connecting the positive Pole of the high-tensiongenerator with the line and the circuit III with the transmittingapparatus. The station B on the contrary has its double lever switches 6and 17 placed on contacts 9 and 11 and contacts 18 and 20 respectively,thus connecting the negative pole of the generator 8 with the line, andthe circuit III with the receiving apparatus. The other poles of thegenerators 8 and 8 are connected to the ground over adjustableself-induction coils 7 and 7 respectively. Now the oscillation circuittraced from ground 13 over cable or line 11 to ground 13, as it has beenstated previously, is charged electrostatically by the high tensiongenerators 8 and 8. This is done by means of the condensers 2 and 2 atthe beginning and the end of the line, the near side condenser plates ofwhich are loaded by the tension of the generators, while the off-sideplates by induction are charging the cable or line up to a tension equalto that of the generator. The impulses given to transmit messages cannow be superposed on this charged line circuit and thereby are freedfrom overcoming the resistance of this circuit. The switch 22 isrepresented turned to contact 23 which leads to the Morse key 25 andwhen this key is operated, a series of interruptions is sent through thecircuits IV and III, which impulses are preferably reinforced by meansof the variable condenser 28 in parallel to the above named circuits. Ateach impulse in the circuit III the circuit II which must be suitablycoupled with the circuit III comes into very slightly dampedoscillations which are superposed on the tension existing in the linecircuit. These oscillations pass condenser 2 cable l1 and condenser 2and penetrate into circuit II which is tuned to the same frequency withcircuit II. This syntonizing as well as the adjustment of the couplingbetween the circuits II and III and II and III respectively is performedby means of the variable condensers 4. and 4: respectively. Preferably acapacitative inductive coupling according to Patent No. 1,116,130, datedNovember 3, 1914, is used for this purpose. The oscillations thusobtained in the circuit II which generate corresponding oscillations inthe coil 15 and thereby in the circuit III now act upon the receivingapparatus 30. It must be noted however that the circuit III ispermanently under the action of a current of low intensity but ofcomparatively high tension, due to the source of current 29 on which theoscillations are superposed thus obtaining an undulatory current to actupon the receiving apparatus 30. With respect to Fig. 2, it should beobserved that the blocking condenser E K prevents the current of lowintensity but of comparatively high tension emanating from the source ofcurrent 29 (Zamboni dry pile, etc.) to spread across the receivingapparatus 30 and to charge the coils appertainingthereto;otherwise theaction is exactly the same as that hereinbefore set forth. For if thecircuit V happens to be without current from the very start, then thesuperimposed alternating currents of the line require comparatively muchtime to charge the condenser 31. However, if the circuit has alreadybeen charged by the high tension source of current 29, then thesuperposed alternating currents of low intensity of the line willsuffice to cause a rapid discharge of the condenser 31.

Of course other arrangements and modifications will be possible andappear to those skilled in the art without departing from the scope ofthe invention.

Claims.

1. In a telegraph and telephone system, a pair of condensers, a lineincluded between said condensers, a grounded generator for eachcondenser, means to change the polar connection of each generator tosaid condensers whereby the positive pole of one generator and thenegative pole of the other generator may be connected to said condensersand vice versa according to the direction of transmission over saidline, a local circuit at each end of the line arranged to superimposeconductive current on that portion of the line between the generator andcondenser, said local circuits including means to adjust them toresonance with one another.

2. In a telegraph and telephone system, a pair of condensers, a lineincluded between them, a grounded generator connected to each condenser,an oscillating circuit includ ing an adjustable capacity includedbetween each generator and its pertaining condenser,

a local circuit including means to impress upon said oscillating circuitcurrent undulations in accordance with signals, a local receivingcircuit at each end of said line includinga capacity and receivingmeans, and a switch controlling the operative relation of the sending orthe receiving circuits to the oscillating circuit, and means to reversethe terminal connections of the generators to line.

3. In a telephone and telegraph system, a line having a certaincapacity, an adjustable self induction at each end of the same to forman oscillating circuit, means to close said circuit, a condenserinserted at each end of the line, generators producing a high voltagecurrent for charging the line connected with terminals of differentpolarity at the ends of the line, said generators being insertedpermanently into the oscillation circuit, a signaling device forsuperimposing oscillating signaling currents upon the permanent highvoltage current charge of the line and a receiver operated by the saidoscillating signaling currents.

4. In a telegraph and telephone system, a line having a certaincapacity, adjustable self inductions at each end of the line to form anoscillation circuit, means to close said circuit, condensers at each endof the line, generators connected with the oscillation circuit withterminals of different polarities at opposite ends of the same toimpress a high voltage charging upon it, ad-

ditional self inductions connected in series with the line each havingan adjustable condenser connected in parallel therewith to form anoscillation circuit tuned to a definite frequency, further selfinductions forming part of an oscillation circuit at each station andtuned to a definite frequency inductively connected with said additionalself inductions of the charged line, a vibration generator and asignaling device in connec- 10 tion With each of the latter oscillationcircuits, and switches adapted to connect said oscillation circuits witha receiving arrangement.

In testimony that I claim the foregoing as my invention, I have signedmy name in 15 Copies of this patent may be obtained for five cents each,by addressing the Commissioner of Patents, Washington, D. C.

